Tuner for electric steel guitar



1968' D. H. JACKSON I ,4 I

TUNER FOR ELECTRIC. STEEL GUITAR Filed Aug. 22, 1966 i 5 Sheets-Sheet 1 1 J l I r' 1/ W 9 8 mu I INVENTOR.

Oct. 29, 1968 JACKSON I 3,407,697

TUNER FOR ELECTRIC STEEL GUITAR.

Filed Aug. 22, 1966 s Sheets-Sheet 2 INVEI VTO RL BY DAVID H. Jhch'solv M MQ- ATTORNEY Oct. 29, 1968 D. H. JACKSON TUNER FOR ELECTRIC STEEL GUITAR 5 Sheets$heet 3 Filed Aug. 22, 1966 INVENTOR. I

DAV/D H 82cm bd zswf zx ATTOZPNEK United States Patent Office 3,407,697 Patented Oct. 29, 1968 3,407,697 TUNER FOR ELECTRIC STEEL GUITAR David H. Jackson, 102 Westchester Court, Madison, Tenn. 37115 Filed Aug. 22, 1966, Ser. No. 573,948 6 Claims. (Cl. 84-312) This invention relates generally to new and useful improvements in electric steel guitars and particularly seeks to provide novel pedal-actuated devices for raising or lowering the pitch of the strings thereof either singly or in groups of two or more.

Therefore, an object of this invention is to provide a tuner. for electric steel guitars capable of raising or lowering the pit-ch of any selected string above or below its originally tuned pitch.

Another object of this invention is to provide a tuner of the character stated which includes a plurality of tensioning fingers each connected to the end of a string and normally maintained in a fixed position for maintaining the original tuned pitch of its connected string but selectively oscillatable in opposite directions to increase or decrease tension on the spring and thus raise or lower its pitch.

Another object of this invention is to provide a tuner of the character stated in which the tensioning fingers are connected to adjustable means for limiting the degree of oscillation in either direction.

Another object of this invention is to provide a tuner of the character stated in which each tensioning finger is provided with a lower extension pivotally attached thereto at its upper end and normally disposed against a pair of vertically spaced abutments to establish and maintain the original or neutral tuned pitch position of the finger.

A further object of this invention is to provide a tuner of the character stated in which the lower finger extension can be pivoted about the lower of the vertically spaced abutments to cause oscillation of the finger in one direction and can be pivoted about the upper of said abutments to cause oscillation of the finger in the opposite direction.

A further object of this invention is to provide a tuner of the character stated in which the pivoting of the lower finger extension is effected by pedal-actuated linkages.

A further object of this invention is to provide a tuner of the character stated in which adjustable stops are provided to positively limit downward movement of the actuating pedals. 7

With these and other objects, the nature of which will become apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.

In the drawings:

FIG. 1 is a perspective view of an electric steel guitar containing tuning devices constructed in accordance with this invention;

FIG. 2 is a fragmentary top plan view of the tail end portion thereof;

FIG. 3 is a fragmentary longitudinal vertical section taken along line 3--3 of FIG. 2;

FIG. 4 is a detail perspective view of one of the tensioning fingers and certain of its associated elements; and

FIG. 5 is a schematic perspective view of the assembled linkage for one tensioning finger.

Referring to the drawings in detail, the invention as illustrated is embodied in an electric steel guitar including a rectangular frame or casing 5 mounted on four re movable adjustable legs 6 and provided with a downwardly extending skirt 7 which conceals the inner mechanisms of the instrument.

An elongated body element 8 having a finger board 9 is mounted on the top of the frame 5 and underlies a plurality of strings 10 which are connected over a bridge 11 to the usual tuning keys 12 at the head end and to the tuning devices of this invention at the tail end.

The tail end of the body element 8 includes side walls 13, a bottom 14 and an end wall 15 that is relieved along its upper edge as at 16 to provide clearance for certain of the tuner elements as will be hereinafter more fully described.

A pair of spaced parallel longitudinally extending side plates 17, 17 (see FIG. 2), each having an upwardly projecting arm 18, are secured intermediate the side walls 13 adjacent the end wall 15.

A pivot shaft 19 spans the upper ends of the arms 18 and oscillatably supports a plurality of tensioning or tuning fingers 20 having semicylindrical upper ends 21 concentric with the shaft 19. The lower end of each finger 20 is bifurcated to define a slot 22 which receives the upper end of a pivot bar 23 pivotally connected thereto as at 24.

The lower tail edge of each pivot bar 23 normally abuts against a fixed transverse bar 25 which also serves as a fulcrum therefor when the pivot bar is pivoted to cause pitch increasing oscillation of the finger 20 as will be hereinafter more fully described. A transverse pivot shaft 26 is alfixed above the bar 25 adjacent the upper end of the pivot bar 23 and carries a plurality of roller abutments 27 engageable with the tail edges of the pivot bars in vertical alignment with the abutment face of the bar 25. The roller abutments 27 also serve as fulcrums for the pivot bar 23 when it is pivoted to cause pitch decreasing oscillation of the fingers 20.

Each finger 20 is provided with a recess 28 which receives one end of an adjusting rod 29 pivotally connected thereto as at 30. The other end of the rod 29 is threaded and passes through a suitable aperture in a fixed transverse abutment bar 31 and extends beyond the end wall 15 in the relieved area 16 thereof. A stop nut 32, compression spring 33 and knurled lowering tuning knob 34 are carried by the rod 29 intermediate the finger 20 and the abutment bar 31; and an oppositely arranged stop nut 35, compression spring 36 and knurled raising tuning knob 37 are carried by the externally projecting portion of the rod 29.

A tension spring 38 has one end afiixed to the pivot bar 23 near the lower end thereof and its other end affixed to the end wall 15 and normally serves to hold the pivot bar 23 against the vertically aligned abut-ments 25 and 27, thus maintaining the finger 20 in its nonnal or neutral pitch position. In this condition both of the tuning knobs 34 and 37 are out of contact 'with the abutment bar 31 and it is possible for the finger 20 to be oscillated a limited amount in either direction by pivoting the pivot bar 23 either on the bar 25 as a fulcrum or on the roller 27 as a fulcrum.

The tail end of the string 10 is attached to the tail face of the finger 20 as at 39 so that the finger were oscillated clockwise about the shaft 19 (as viewed in FIG. 3) greater tension would be applied to the string and its pitch would be raised. Counterclockwise oscillation of the finger 20 would, of course, create the opposite effect and the pitch would be lowered. Clockwise oscillation is limited by contact between the tuning knob 37 and the abutment 31, and of course, the knob 37 is adjusted to the required position on the rod 29 to permit the desired increase in pitch. Similarly, the lowering tuning knob 34 is adjusted to its required position to permit the desired decrease in pitch following counterclockwise oscillation of the finger.

As usual, a magnetic pickup unit 40 is mounted immediately beneath the strings 10 just ahead of the fingers 20.

The fingers 20 are individually and selectively operated by pedal and linkage means that include a pedal bar 41 *aflixed to one end of a transverse rock shaft 46 provided with a longitudinal keyway 47. A downwardly extending normally vertical, rock arm 48 is keyed to the shaft 46 for adjustment-along the length thereof to'a position aligned with any desired finger 2t) and is provided with a lower aperture 49 and an upper aperture 59' (see FIG. 3).

A pull rod 51 extends between the rock arm 48 and the pivot bar 23 and as shown in FIG. 3, has one end p'rojecting through the rock arm aperture 50 and fitted with a removable collar 52, and its other end pivotally connected to the upper part of the pivot bar 23 through a C- link 53. The pivot bar 23 is provided with upper and lower sets of holes 54 and 55 for varying such C-link connections. V

For example, with the pull rod 51 conected as described above, depression of the pedal '43 will cause the pull rod to pull the upper end of the pivot bar 23 away from the roller abutment 27 (against the combined force exerted by tension on the string and the tension spring 38) while permitting its lower end to fulcrum on the bar 25, thus oscillating the finger in a clockwise direction about the shaft 19 to increase the tension of the string 10 and raise its pitch. As this movement takes place the rod 29 is pulled to the left until the tuner knob 37 contacts the bar 31, thus preventing further movement and establishing the desired pitch increase.

On the other hand, if the pull rod 51 were connected through the aperture 49 of he rock arm 48 and to one of the lower holes 55 of the pivot bar 23, depression of the pedal 43 will cause the pull rod to pull the lower end of the pivot bar 23 away from the abutment bar 25 while permitting its upper part to fulcrum on the roller 27, thus oscillating the finger 20 in a counterclockwise direction about the shaft 19 to decrease the tension of the string 10 and lower its pitch. As this movement takes place the rod 29 is pushed to the right until the tuner knob'34 contacts the bar 31, thus preventing further movenient'and establishing the desired pitch decrease.

The rock arm'48 may be spring biased as schematically indicated at 56 to maintain the pedal 43 in its normally raised position and the rock arm 45 in its normally horizontal position with its outer end pressing against a cushion 57.

An adjustable pedal stop 58 is positioned beneath the rock arm 45 and is set to terminate or limit downward movement of the pedal at the moment the tuning knob 37 (or 34) contacts the abutment bar 31.

Alhtough for the purpose of simplicity in illustration only one set of finger operating linkages has been shown, it will be appreciated that there will be pedal andlinkage connections for the finger of each string that is to be subjected to a selective change of pitch, and that certain of the fingers will be connected to effect an increase in pitch while others will' be connected to etfect a decrease in pitch.

In preparing the instrument for play the strings 10 are first properly tuned by the tuning pegs 12 with the fingers 20 in the neutral position shown'in FIG. 3 and the tuning knobs 3'4 and 37 backed oif away from engagement with the bar 31. The pedal stop 58 is also backed ofl? to permit free pedal movement. Then the pedals for each string are successively depressed until the desired degree of pitch increase (or decrease) has ben reached, at which point the tuning knob 37 (or 34) is turned in until it firmly abuts the bar 31 to set or fix the pitch change and the pedal stop 58 is advanced until it firmly contacts the lower face of the rock arm 45, thus establishing the lower limit of pedal movement for the desired pitch change. Although the illustrated embodiment of this invention is directed to a pedal steel guitar, it will be appreciated that the principles of this invention are equally applicable to any other type of stringed instrument; In certain of such other embodiments the pedals would be replaced by pivoted levers attached to suitable parts of the instruments if the instruments are hand held.

I claim: 1. In a stringed instrument having an elongated body provided with a plurality of parallel vibratable' strings under tension secured at their head ends to a plurality of tuning pegs and at their tail ends to tension varying means, said tension varying means including a pivot shaft extending transversely with respect to said strings and located below the plane thereof, a downwardly extending finger pivotally mounted on said pivot shaft and having a semicylindrical upper end concentric to said pivot shaft for supporting the tail end portion of a string, means for securing the tail end of said string to said finger, a depending pivot bar pivotally attached at its upper end to the lower end of said finger about an axis parallel to said pivot shaft, a pair of vertically spaced fulcrum abutments contacting the tail edge of said pivot bar, resilient means for normally maintaining said pivot bar in contact with said vertically spaced abunments, the tension on said string additionally nonmally assisting in maintaining said pivot bar in contact therewith by tending to rotate said finger about said pivot shaft in a direction to cause the lower end of said finger to move toward the plane of said vertically spaced abutments, and selectively connectable means for pulling the top of said pivot bar away from the upper of said vertically spaced abutments while retaining the bottom of said pivot bar in contact with the lower thereof whereby to oscillate said finger in a direction to increase the tension on and pitch of said string or for pulling the bottom of said pivot bar away from the lower of said vertically spaced abutments while retaining upper portion of said pivot bar in contact with the upper-thereof whereby to oscillate said finger in a direction to decrease the tension on and pitch of said string.

2. The stringed instrument of claim 1 additionally including adjustable means operably connected to said finger for limiting its oscillatory motion in either direction.

3. The stringed instrument of claim 2 in which said selectively connectable means are pedal actuated.

4. The stringed instrument of claim 3 additionally including a pedal stop adjustableto stop movement of said pedal coincidentally with the finger movement limiting action of said adjustable means.

5. The stringed instrument of claim 3 in which said tension varying means are provided for all of said strings.

6. The stringed instrument of claim 4 in which said tension varying means are provided for all of said strings.

References Cited UNITED STATES PATENTS 3,014,395 12/1961 Blair 84--312 2,458,263 1/1949 Harlin 84-312 2,973,682 3/1961 Fender 84312 

1. IN A STRINGED INSTRUMENT HAVING AN ELONGATED BODY PROVIDED WITH A PLURALITY OF PARALLEL VIBRATABLE STRINGS UNDER TENSION SECURED AT THEIR HEAD ENDS TO A PLURALITY OF TUNING PEGS AND A THEIR TAIL ENDS TO TENSION VARYING MEANS, SAID TENSION VARYING MEANS INCLUDING A PIVOT SHAFT EXTENDING TRANSVERSELY WITH RESPECT TO SAID STRINGS AND LOCATED BELOW THE PLANE THEREOF, A DOWNWARDLY EXTENDING FINGER PIVOTALLY MOUNTED ON SAID PIVOT SHAFT AND HAVING A SEMICYLINDRICAL UPPER END CONCENTRIC TO SAID PIVOT SHAFT FOR SUPPORTING THE TAIL END PORTION OF A STRING, MEANS FOR SECURING THE TAIL END OF SAID STRING TO SAID FINGER, A DEPENDING PIVOT BAR PIVOTALLY ATTACHED AT ITS UPPER END TO THE LOWER END OF SAID FINGER ABOUT AN AXIS PARALLEL TO SAID PIVOT SHAFT, A PAIR OF VERTICALLY SPACED FULCRUM ABUTMENTS CONTACTING THE TAIL EDGE OF SAID PIVOT BAR, RESILIENT MEANS FOR NORMALLY MAINTAINING SAID PIVOT BAR IN CONTACT WITH SAID VERTICALLY SPACED ABUTMENTS, THE TENSION ON SAID STRING ADDITIONALLY NORMALLY ASSISTING IN MAINTAINING SAID PIVOT BAR IN CONTACT THERWITH BY TENDING TO ROTATE SAID FINGER ABOUT SAID PIVOT SHAFT IN A DIRECTION TO CAUSE THE LOWER END OF SAID FINGER TO MOVE TOWARD THE PLANE OF SAID VERTICALLY SPACED ABUTMENTS, AND SELECTIVELY CONNECTABLE MEANS FOR PULLING THE TOP OF SAID PIVOT BAR AWAY FROM THE UPPER OF SAID VERTICALLY SPACED ABUTMENTS WHILE RETAINING THE BOTTOM OF SAID PIVOT BAR IN CONTACT WITH THE LOWER THEREOF WHEREBY TO OSCILLATE SAID FINGER IN A DIRECTION TO INCREASE THE TENSION ON AND PITCH OF SAID STRING OR FOR PULLING THE BOTTOM OF SAID PIVOT BAR AWAY FROM THE LOWER OF SAID VERTICALLY SPACED ABUTMENTS WHILE RETAINING UPPER PORTION OF SAID PIVOT BAR IN CONTACT WITH THE UPPER THEREOF WHEREBY TO OSCILLATE SAID FINGER IN A DIRECTION TO DECREASE THE TENSION ON AND PITCH OF SAID STRING. 